Fire/EMS Safety, Health and Survival Week: Day Four -The New Fire Ground

Fire/EMS Safety, Health and Survival Week: Day Four -The New Fire Ground    


There is an immediate need for today’s emerging and operating command and company officers to increase their foundation of knowledge and insights related to the modern building occupancy, building construction and fire protection engineering and to adjust and modify traditional and conventional strategic operating profiles in order to safeguard companies, personnel and team compositions.

Strategies and tactics must be based on occupancy risk, not occupancy type, and must have the combined adequacy of sufficient staffing, fire flow and tactical patience orchestrated in a manner that identifies with the fire and building profiling, predictability of the occupancy profile and accounts for presumptive fire behavior. It is not your old method of size-up and operational deployment.

The dramatic changes in buildings and occupancies over the past ten years have resulted inadequate fire suppression methodologies based upon conventional practices that do not align with the manner in which we used to discern with a measured degree of predictability how buildings would perform, react and fail under most fire conditions. These past presumptions, which many of us debated with our esteemed colleagues, are being validated through empirical data resulting from the cutting edge research and testing being conducted today by UL and NIST.

Predicting Fire Behavior and Building Stability

We predicate certain expectations that fire will travel in a defined (predictable) manner that fire will hold within a room and compartment for a predictable given duration of time; that the fire load and related fire flows required will be appropriate for an expected size and severity of fire encountered within a given building, occupancy, structural system and given an appropriately trained and skilled staff to perform the requisite evolutions, we can safely and effectively mitigate a structural fire situation in any  given building type and occupancy.

  • Past operational experiences, both favorable and negative; gave us experiences that define and determine how the fireground is assessed, react and how we expect similar structures and occupancies to perform at a given alarm in the future; this formed the basis for the naturalistic decision-making process.

Implementing fundamentals of firefighting operations built upon nine decades of time-tested and experience-proven strategies and tactics continues to be the model of suppression operations. These same fundamental strategies continue to drive methodologies and curriculums in our current training programs and academies of instructions.

Are you aware of the defining changes in structural systems and support, the degree of compartmentation,

  • the characteristics of materials and the magnitude of the fire-loading package in today’s buildings and occupancies?
  • When was the last time you were out in the street with the companies, or spent some time doing a walk-through of construction or renovations site?
  • Have you asked you commanding officers, division or battalion chief or your company officers for insights into what operational demands and risks are being imposed upon them while operating in the street and within the buildings, occupancies and structures that comprise your jurisdiction?

The structural anatomy, predictability of building performance under fire conditions, structural integrity and the extreme fire behavior; accelerated growth rate and intensively levels typically encountered in buildings of modern construction during initial and sustained fire suppression have given new meaning to the term combat fire engagement.

It’s no longer just brute force and sheer physical determination that define structural fire suppression operations, although any seasoned command and company officer knows that at times. It’s what gets the job done under the most arduous and demanding of circumstances.

However, from a methodical and disciplined perspective; aggressive firefighting must be redefined and aligned to the built environment and associated with goal-oriented tactical operations that are defined by risk assessed and analyzed strategic processes that are executed under battle plans that promote the best in safety practices and survivability within known hostile structural fire environments.

The demands and requirements of modern firefighting will continue to require the placement of personnel within situations and buildings that carry risk, uncertainty and inherent danger. As a result, risk management must become fluid and integrated with intelligent tactical deployments and operations recognizing the risk problematically and not fatalistically, resulting in safety conscious strategies and tactics.

Today’s incident commanders need to think about the Predicative Strategic Process, refined Tactical Deployment Models integrating intelligent Structural Anatomy and Predictive Occupancy Profiling, while implementing Tactical Patience.

Think about the following;

  • Read, comprehend and implement the new IAFC The Rules of Engagement for Firefighter Survival and The Incident Commanders Rules of Engagement for Firefighter Safety
  • Take a tour of your response area, district, community or city.
  • Take a good look around and begin to recognize the apparent or subtle changes that are affecting your incident operations; Take note and think about what needs to be adjusted, modified or changed in your operations.
  • Read up on the latest research and technical literature on wind driven fires, extreme fire behavior, structural ability of engineered lumber systems, fire loading and suppression theory
  • Take the time to personally read a series of the latest NIOSH Fire Fighter Fatality Investigation and Prevention Program LODD reports and relate them to your organizations operations and jurisdictional risks.
  • Start thinking in terms of Occupancy Risks versus Occupancy Type and align your operations and deployments to match those risks
  • Increase your situational awareness of today’s fireground and refine your strategic and tactical modeling
  • Implement both Strategic and Tactical Patience; Slow down and allow the building to react and stabilize, for fire behavior to stop behaving badly and for your companies to increase survivability ratios while meeting the demands of  conducting fire service operations
  • Think about Adaptive Fire Ground Management and Command Resiliency
  • Reprogram your assumptions and presumptions and options on building construction and firefighting operations; the buildings have changed, our firefighting has not; what are you going to do about that gap?

If you don’t fully understand how a building truly performs or reacts under fire conditions and the variables that can influence its stability and degradation, movement of fire and products of combustion and the resource requirements for fire suppression in terms of staffing, apparatus and required fire flows, then you will be functioning and operating in a reactionary manner that is no longer acceptable within many of our modern building types, occupancies and structures.

This places higher risk to your personnel and lessens the likelihood for effective, efficient and safe operations. You’re just not doing your job effectively and you’re at risk. These risks can equate into insurmountable operational challenges and could lead to adverse incident outcomes. Someone could get hurt, someone could die, it’s that simple; it’s that obvious.

Without understanding the building-occupancy relationships and integrating; construction, occupancies, fire dynamics and fire behavior, risk, analysis, the art and science of firefighting, safety conscious work environment concepts and effective and well-informed incident command management, company-level supervision and task-level competencies … You are derelict and negligent and “not “everyone may be going home”.

It’s all about understanding the building-occupancy relationships and the art and science of firefighting, equating to Building Knowledge = Firefighter Safety.


Taking it to the StreetsTM is a monthly radio show featured on BlogTalk Radio and is hosted by nationally renowned fire service leader Christopher Naum, a  36-year fire service veteran and highly regarded national instructor, author, lecturer and fire officer and  the distinguished leading  national authority on building construction and fire ground operations.  Taking it to the StreetsTM is a Series and Production,   © 2011 All Rights Reserved 

Check out the latest downloads of recent programs in the archives by visiting Taking it to the Street’s webpage on or for program insights at    

  • HERE
  • Taking it to the Streets Radio Programs, HERE and HERE 
  •, HERE

 A Series and Firefighter Production


Taking it to the Streets had its premier July 21st on Firefighter with a lively and provoking discussion on “What’s on YOUR Radar Screen?” The program theme aligned with a recent posting on the same topic. Joining me on the program were two prominent and nationally recognized fire service leaders, who I’m honored to have known for many years, Chief Billy Hayes and Chief Doug Cline; the program explored leading fire service issues affecting firefighter safety, training, credentialing and education; fireground operational variables related to the continuing changes in building construction, engineered systems and extreme fire behavior,  and the emerging need for “Tactical Patience” as I’ve been exploring the relationships towards the need for tactical enhancements to our current fire suppression theory and firefighting models.

Conversations expanded on the NFFF/Everyone Goes Home Campaign and programs, the newest EGH initiatives on Behavioral Health and the successes achieved through the Courage to be Safe Programs and the Advocacy Program.

The Premiere of Christopher Naum’s “Taking It to the Streets”

// Podcast: Play in new window | Download

Taking it to the Streets premiered  on  Wednesday July 21st 9:00pm ET

Download the Program HERE

The New Fire Ground

NIST Wind Driven Fire Study

  • Smoke and heat spreading through the corridors and the stairs of a building during a fire can limit building occupants’ ability to escape and can limit fire fighters’ ability to rescue them.  Changes in the building’s ventilation or presence of an external wind can increase the energy release of the fire.  This can also increase the spread of fire gases through the building.  In some cases, such as the Cook County Administration Building fire in October 2003, the fire gas flow, into the corridors and the stairway prevented fire fighters from suppressing the fire from inside the structure.  This fire resulted in 6 building occupant fatalities and fire fighter injuries in the stairway.  The Fire Department of New York City has experienced many wind driven fire incidents which have resulted in fire fighter fatalities and injuries, as have a number of other incidents nationally that have resulted in increased research into this operational and tactical challenge.
  • What tactics or tools are appropriate for use with a wind driven fire and how should the tactics or tools be implemented?  Positive Pressure Ventilation (PPV) is being used by fire departments on smaller structures, such as single family homes, to control the fire flow by introducing pressure from the front door and venting the house through a strategic exit opening.  If done correctly, this tactic can remove significant amounts of heat and smoke from the structure, thus improving the fire fighters’ working environment and improving the chances of survival for the building occupants.  NIST has completed several studies which have a two fold impact: 1) providing guidance on the safe use of PPV and 2) characterizing and validating the modeling of PPV with a computational fluid dynamics (CFD) computer model, so that the model can be used as a training tool for the fire service.
  • This project extends previous work for ventilation under wind driven conditions.  There are many questions regarding wind driven fires.  For example can these PPV fans be used successfully under wind driven fire conditions in large structures?  Large structures, such as high rise buildings, provide additional challenges to fire fighter and building occupant safety: increased travel distance (exposure time), more complicated egress path, and potentially larger fires.  In 2002 there were 7,300 reported fires in high rise structures.
  • Other tactics incorporating devices, such as wind control devices (WCD) to control the ventilation conditions or the use of a “high rise” nozzle from the floor below the fire floor have been tried by the fire service under “real fire” conditions with varying levels of success.
  • A comprehensive free DVD set from the NIST includes a presentation video that explains PPV, examines the results of NIST’s PPV research, and closes with a focus on the use of PPV tactics in high-rise buildings.  All of the NIST PPV reports referenced in the presentation are included on Disc 1 of the set.  All of the videos from the high-rise fire experiments are also provided with a user-friendly, graphic menu that can be used on a PC or a DVD player.  NIST, with support from USFA, DHS, and fire departments across the country, has taken engineering principles and applied them to fire service PPV tactics in order to improve fire fighter safety
  • NIST References HERE and HERE

NIST Fire Fighting Tactics Under Wind Driven Conditions: Laboratory Experiments

  • A series of experiments was conducted in our Large Fire Laboratory to examine the impact of wind control curtains and externally applied hose streams on a wind driven fire.  The results from these experiments will allow us to better understand the fire dynamics within a structure and provide guidance as to the important measurements needed in the future experiments in a high-rise on Governor’s Island in New York City.
  • Fire Fighting Tactics Under Wind Driven Conditions Report, HERE
  • Reference Data HERE

NIST Firefighter Safety and Deployment Study; Report on Residential Fireground Field Experiments

  • The NIST Firefighter Safety and Deployment Study; Titled- Report on Residential Fireground Field Experiments was recently released to the public providing . A copy of the report is attached.
  • Report Abstract:
  • Service expectations placed on the fire service, including Emergency Medical Services (EMS), response to natural disasters, hazardous materials incidents, and acts of terrorism, have steadily increased. However, local decision-makers are challenged to balance these community service expectations with finite resources without a solid technical foundation for evaluating the impact of staffing and deployment decisions on the safety of the public and firefighters. For the first time, this study investigates the effect of varying crew size, first apparatus arrival time, and response time on firefighter safety, overall task completion, and interior residential tenability using realistic residential fires.
  • This study is also unique because of the array of stakeholders and the caliber of technical experts involved. Additionally, the structure used in the field experiments included customized instrumentation; all related industry standards were followed; and robust research methods were used. The results and conclusions will directly inform the NPFA 1710 Technical Committee, who is responsible for developing consensus industry deployment standards.
  • This report presents the results of more than 60 laboratory and residential fireground experiments designed to quantify the effects of various fire department deployment configurations on the most common type of fire—a low hazard residential structure fire. For the fireground experiments, a 2,000 sq ft (186 m2), two-story residential structure was designed and built at the Montgomery County Public Safety Training Academy in Rockville, MD. Fire crews from Montgomery County, MD and Fairfax County.
  • Report results quantify the effectiveness of crew size, first-due engine arrival time, and apparatus arrival stagger on the duration and time to completion of the key 22 fireground tasks and the effect on occupant and firefighter safety.
  • The report is also available for download at the NIST, HERE
  • Synopsis HERE

USFA/NIST Trends in Firefighter Fatalities Due to Structural Collapse, 1979-2002

  • Between the years 1979 and 2002 there were over 180 firefighter fatalities due to structural collapse, not including those firefighters lost in 2001 in the collapse of the World Trade Center Towers. Structural collapse is an insidious problem within the fire fighting community. It often occurs without warning and can easily cause multiple fatalities.
  • As part of a larger research program to help reduce firefighter injuries and fatalities the U.S. Fire Administration (USFA) funded the National Institute of Standards and Technology (NIST) to examine records and determine if there were any trends and/or patterns that could be detected in firefighter fatalities due to structural collapse. If so, these trends could be brought immediately to the attention of training officers and incident commanders and investigated further to determine probable causes.
  • Report: Trends in Firefighter Fatalities Due to Structural Collapse1979-2002

UL Fire Academy CBT

  • UL Structural Stability of Engineered Lumber in Fire Conditions
  • Base on the UL research and
  • This two-hour presentation summarizes a research study on the hazards posed to firefighters by the use of lightweight construction and engineered lumber in floor and roof designs. This free on-line computer based presentation will allow fire professionals to better interpret fire hazards and assess risk for life safety of building occupants and firefighters.
  • This online firefighter training course is the result of a research partnership among UL, the Chicago Fire Department, IAFC, and Michigan State University, funded in part by the U.S. Department of Homeland Security. This self-guided course, which focuses on the structural stability of engineered lumber under fire conditions, is targeted toward the 1.1 million fire service personnel in the United States and Canada. The knowledge developed and shared in this course is critically important to firefighter and civilian safety.
  • This two-hour presentation summarizes a research study on the hazards posed to firefighters by the use of lightweight construction and engineered lumber in floor and roof designs. This free on-line computer based presentation will allow fire professionals to better interpret fire hazards and assess risk for life safety of building occupants and firefighters.
  • Program Objectives:
  • Provide brief history of events leading up to DHS Grant tests
  • Identify the fire test hypothesis, parameters, and steps completed in the testing process
  • Compare tests results (legacy vs. modern construction)
  • Communicate learnings from our partners representing the fire service
  • Discuss code recommendations
  • UL University on-line Program HERE

Fire Behavior 101; Taking it to the Streets



Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction

For many of you that have been following my writings and perspectives on building construction, firefighting, command risk management and operational excellence for firefighter safety have long recognized that I have been promoting and advocating the fact the fireground is changing, our strategies and tactics demand change and does the demand for increased knowledge within the areas of building construction, fire dynamics, while integrating the art and science of firefighting. The most recent release of the testing report from Underwriters Laboratories; Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction and the accompanying empirical data further validates assumptions and premises that many of us shared based upon field observations and first hand incident operations related to the dramatic changes being witnessed as a result of operational challenges in a wide variety of occupancies and building types.

This material is a must read for all emerging and practicing company and command officers ( for starters) to being grasping the magnitude and extent of quantifiable data that supports the premise that combat fire engagement and suppression operations and the rules of engagement are going to change and that change is fast approaching.

Here’s the executive summary of the report and findings from UL. For an download of the entire UL Report, go HERE.

The results of these experiments provide knowledge for the fire service for them to examine their thought processes, standard operating procedures and training content. Several tactical considerations were developed utilizing the data from the experiments to provide specific examples of changes that can be adopted based on a departments current strategies and tactics.

Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Program, Underwriters Laboratories examined fire service ventilation practices as well as the impact of changes in modern house geometries.

There has been a steady change in the residential fire environment over the past several decades. These changes include larger homes, more open floor plans and volumes and increased synthetic fuel loads. This series of experiments examine this change in fire behavior and the impact on firefighter ventilation tactics.

This fire research project developed the empirical data that is needed to quantify the fire behavior associated with these scenarios and result in immediately developing the necessary firefighting ventilation practices to reduce firefighter death and injury.

  • Two houses were constructed in the large fire facility of Underwriters Laboratories in Northbrook, IL.
  • The first of two houses constructed was a one-story, 1200 ft2, 3 bedroom, 1 bathroom house with 8 total rooms.
  • The second house was a two-story 3200 ft2, 4 bedroom, and 2.5 bathroom house with 12 total rooms.
  • The second house featured a modern open floor plan, two story great room and open foyer.

 Fifteen experiments were conducted varying the ventilation locations and the number of ventilation openings. Ventilation scenarios included ventilating the front door only, opening the front door and a window near and remote from the seat of the fire, opening a window only and ventilating a higher opening in the two-story house.

One scenario in each house was conducted in triplicate to examine repeatability. The results of these experiments provide knowledge for the fire service for them to examine their thought processes, standard operating procedures and training content. Several tactical considerations were developed utilizing the data from the experiments to provide specific examples of changes that can be adopted based on a departments current strategies and tactics.

Room Flashover from Sofa Fire


The tactical considerations addressed include:

  • Stages of fire development: The stages of fire development change when a fire becomes ventilation limited.
    • It is common with today’s fire environment to have a decay period prior to flashover which emphasizes the importance of ventilation
  • Forcing the front door is ventilation: Forcing entry has to be thought of as ventilation as well.
    • While forcing entry is necessary to fight the fire it must also trigger the thought that air is being fed to the fire and the clock is ticking before either the fire gets extinguished or it grows until an untenable condition exists jeopardizing the safety of everyone in the structure.
  • No smoke showing: A common event during the experiments was that once the fire became ventilation limited the smoke being forced out of the gaps of the houses greatly diminished or stopped all together.
    • No some showing during size-up should increase awareness of the potential conditions inside.
  • Coordination: If you add air to the fire and don’t apply water in the appropriate time frame the fire gets larger and safety decreases.
    • Examining the times to untenability gives the best case scenario of how coordinated the attack needs to be.
    • Taking the average time for every experiment from the time of ventilation to the time of the onset of firefighter untenability conditions yields 100 seconds for the one-story house and 200 seconds for the two-story house
    • In many of the experiments from the onset of firefighter untenability until flashover was less than 10 seconds.
    • These times should be treated as being very conservative. If a vent location already exists because the homeowner left a window or door open then the fire is going to respond faster to additional ventilation opening because the temperatures in the house are going to be higher.
    • Coordination of fire attack crew is essential for a positive outcome in today’s fire environment.
  • Smoke tunneling and rapid air movement through the front door: Once the front door is opened attention should be given to the flow through the front door.
    • A rapid in rush of air or a tunneling effect could indicate a ventilation limited fire.
  • Vent Enter Search (VES): During a VES operation, primary importance should be given to closing the door to the room.
    • This eliminates the impact of the open vent and increases tenability for potential occupants and firefighters while the smoke ventilates from the now isolated room.
  • Flow paths: Every new ventilation opening provides a new flow path to the fire and vice versa.
    • This could create very dangerous conditions when there is a ventilation limited fire.
  • Can you vent enough?: In the experiments where multiple ventilation locations were made it was not possible to create fuel limited fires.
    • The fire responded to all the additional air provided.
    • That means that even with a ventilation location open the fire is still ventilation limited and will respond just as fast or faster to any additional air.
    • It is more likely that the fire will respond faster because the already open ventilation location is allowing the fire to maintain a higher temperature than if everything was closed. In these cases rapid fire progression if highly probable and coordination of fire attack with ventilation is paramount.
  • Impact of shut door on occupant tenability and firefighter tenability: Conditions in every experiment for the closed bedroom remained tenable for temperature and oxygen concentration thresholds.
    • This means that the act of closing a door between the occupant and the fire or a firefighter and the fire can increase the chance of survivability.
    • During firefighter operations if a firefighter is searching ahead of a hoseline or becomes separated from his crew and conditions deteriorate then a good choice of actions would be to get in a room with a closed door until the fire is knocked down or escape out of the room’s window with more time provided by the closed door
  • Potential impact of open vent already on flashover time: All of these experiments were designed to examine the first ventilation actions by an arriving crew when there are no ventilation openings.
    • It is possible that the fire will fail a window prior to fire department arrival or that a door or window was left open by the occupant while exiting.
    • It is important to understand that an already open ventilation location is providing air to the fire, allowing it to sustain or grow.
  • Pushing fire: There were no temperature spikes in any of the rooms, especially the rooms adjacent to the fire room when water was applied from the outside. It appears that in most cases the fire was slowed down by the water application and that external water application had no negative impacts to occupant survivability.
    • While the fog stream “pushed” steam along the flow path there was no fire “pushed”.
  • No damage to surrounding rooms: Just as the fire triangle depicts, fire needs oxygen to burn.
    • A condition that existed in every experiment was that the fire (living room or family room) grew until oxygen was reduced below levels to sustain it.
    • This means that it decreased the oxygen in the entire house by lowering the oxygen in surrounding rooms and the more remote bedrooms until combustion was not possible.
    • In most cases surrounding rooms such as the dining room and kitchen had no fire in them even when the fire room was fully involved in flames and was ventilating out of the structure.

Online Training Program

In order to make the results of this study more user friendly for the fire service to examine, UL developed an online interactive training module that can be viewed by clicking here. The program includes a professionally narrated description of all of the experiments, their results and the tactical considerations. Experimental video is used and graphical data is explained in a way that brings science to the street level firefighter.

UL University On-Line CBT



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